Association of Age of Metabolic Syndrome Onset With Cardiovascular Diseases: The Kailuan Study.

Background: Metabolic syndrome (MetS) is associated with an increased risk of incident cardiovascular diseases (CVD), but the association between the new-onset MetS at different ages and the CVD risk remain unclear. Methods: This was a prospective study comprising a total of 72,986 participants without MetS and CVD who participated in the Kailuan study baseline survey (July 2006 to October 2007). All participants received the biennial follow-up visit until December 31, 2019. In addition, 26,411 patients with new-onset MetS were identified from follow-up, and one control participant was randomly selected for each of them as a match for age ( ± 1 year) and sex. In the end, a total of 25,125 case-control pairs were involved. Moreover, the Cox proportional hazard model was established to calculate the hazard ratios (HR) for incident CVD across the onset age groups. Results: According to the median follow-up for 8.47 years, 2,319 cases of incident CVD occurred. As MetS onset age increased, CVD hazards gradually decreased after adjusting for potential confounders. Compared with non-MetS controls, the HR and the 95% confidence interval (CI) for CVD were 1.84 (1.31-2.57) in the MetS onset age <45 years group, 1.67 (1.42-1.95) for the 45-54 years group, 1.36 (1.18-1.58) for the 55-64 years group, and 1.28 (1.10-1.50) for the ≥65 years group, respectively (p for interaction = 0.03). Conclusions: The relative risks of CVD differed across MetS onset age groups, and the associations was more intense in the MetS onset group at a younger age.